1. Field of the Invention
The present invention relates to an electrophotosensitive material used for electrophotographic copying, laser printer and the like. More specifically, the invention relates to an electrophotosensitive material containing a novel charge-generating agent and having high sensitivity and excellent recurring property.
2. Description of the Prior Art
It has long been known that a disazo pigment is effectively used as a photoconducting material or a charge-generating agent for the electrophotosensitive material, and those disazo pigments having a variety of chemical structures have been proposed in, for example, Japanese Patent Publication Laid-Open No. 37453/1972, Japanese Patent Publication No. 63902/1988 and Japanese Patent Publication Laid-Open No. 39159/1990.
Disazo pigments exhibit excellent properties when they are used as charge-generating agents. However, there has not yet been provided a photosensitive material using disazo pigment which exhibits recurring property to a satisfactory degree. This is because, NOx and 03 are generated in the step of charging in the electrophotographic processing, and the azo pigment is deteriorated or decomposed being attacked by them. It has therefore been desired to develop a disazo pigment that withstands attacks by them.
In the field of electrophotographic copying, furthermore, it has been urged to develop a charge-generating agent which has a high sensitivity or a large charge-generating efficiency to meet the demand for increasing the copying speed.